Americans involved in the US Ferguson demonstrations joined British activists on Tuesday to block a major street in central London in protest at security company G4S’s role in the death of Jimmy Mubenga. The tactic of blocking traffic – known as “shutting shit down” – has been quite prominent in the protests to show solidarity with Michael Brown, Eric Garner and other black people killed by police in the US.

Patrisse Cullors, co-founder of the Black Lives Matter movement and headline speaker for the Ferguson Solidarity Tour, explained how effective the tactic has been in the States. “We’ve been shutting shit down since August 9th [2014] both in Ferguson [where Michael Brown was killed, sparking riots and protests] but throughout the entire country, including where I live in Los Angeles, where we’ve been able to occupy the headquarters of the LAPD for seven days, and this is a common practice, of shutting shit down,” she said.

Activists from the UK NUS’s Black Students’ Campaign, Defend the Right to Protest Campaign, and the Ferguson Solidarity Tour were also campaigning against the private prisons G4S operates and its involvement in the occupied West Bank.